In Fallout Shelter Online, players manage a Vault, constructing facilities, recruiting iconic heroes from the Fallout series, and engaging in strategic gameplay that includes team-building and PvP elements. The game emphasizes resource management and tactical decision-making as players navigate the challenges of survival in a post-apocalyptic world.

The storyline of Fallout Shelter Online revolves around the player's quest to uncover the mystery of the missing Overseer while ensuring the safety and prosperity of their Vault's inhabitants. Players explore the Wasteland, encountering various challenges and adventures along the way.

Fallout Shelter Online stands out with its integration of multiplayer elements, allowing players to compete against each other in PvP battles, as well as its rich roster of characters and lore drawn from the expansive Fallout franchise.